Temporal Dynamics of Higher Order Aberrations in the Human Eye: A Comprehensive Study Across Morning and Evening

Study description

Title

Temporal
Dynamics of Higher Order Aberrations in the Human Eye: A
Comprehensive Study Across Morning and Evening

Examiner

Illes Tibor

Background of the study topic

This
study delves into the dynamic nature of higher order aberrations
(HOAs) in the human eye at different times of the day: morning and
evening. HOAs are optical imperfections that persist even after
correcting for spherical defocus and astigmatism, affecting
retinal image quality. With evidence suggesting that visual
experiences influence ocular growth, we aim to explore whether
variations in HOAs during different times of the day contribute to
the regulation of eye growth and refractive error development.
Understanding these temporal fluctuations in HOAs could provide
valuable insights for refining strategies to manage refractive
errors and optimizing visual performance.

Study description

Explore
the fluctuating optics of the human eye throughout the day in our
study. Investigating morning and evening variations, we aim to
uncover insights into how these optical imperfections impact eye
growth and refractive error development.

Study definitions

Study design

Analytical,
Longitudinal, Prospective, Experimental, Monocentric

Primary aim

Difference
in HOA
in the human eye vary throughout the day

Primary hypothesis

There
is no difference in HOA in the human eye vary throughout the day

Secondary aim(s)

Differences
in higher order aberrations (HOAs) concerning age

Secondary
hypotheses

There
is no differences
in higher order aberrations (HOAs) concerning age

Study organization

Materials / devices / software

–
Autorefractor
(Zeiss iProfiler)

-Phoropter

-Statistical
Software SPSS

-Wavefront
Aberrometer (Zeiss
iProfiler)

-Patient
Data Recording System

-Clinical
Examination Room

-Consent
Forms and Ethical Approval

Sample size

–Approx.
18 participants

Inclusion &
exclusion criteria

Inclusion
criteria:

Age
Range – Participants aged between 18 and 60 years.

Refractive
Error – Both individuals with high refractive error (e.g., myopia,
hyperopia, astigmatism) and those with normal or low refractive
error in range of spherical
refractive error max ±8dpt, cyl max -6dpt

Visual
Acuity – Individuals with a best-corrected visual acuity of 20/20
or better.

Good
General Health – Participants without significant systemic or
ocular health conditions that could affect study outcomes.

Exclusion
criteria

Previous
Eye Surgery – Individuals who have undergone refractive or
cataract surgery.

Ocular
Pathologies – Those with ocular pathologies such as glaucoma,
retinal disorders, or corneal abnormalities.

Pregnancy
– Exclusion of pregnant women due to potential hormonal influences
on the eyes.

Contact
Lens Wear – Individuals wearing contact lenses to be excluded due
to potential effects on wavefront measurements.

Systemic
Medications – Participants on medications known to influence
ocular parameters.

Inability
to Provide Informed Consent – Individuals unable to comprehend the
study requirements or provide informed consent.

Uncontrolled
Systemic Conditions – Exclusion of participants with uncontrolled
diabetes or hypertension.

Measurement
procedure

1. Participant
   Preparation

1. Autorefraction
   ( Wavefront
   Aberrometer)

2. VA
   testing with phoropter

3. Data
   Collection

4. Repeated
   Measures (if applicable)

5. Data
   Analysis

6. Quality
   Control

7. Ethical
   Considerations

8. Documentation
   of all measurements after collecting and calculating data

Randomization

Participant
assignment to specific conditions will be randomized during the
measurement sessions

Control factors

1. Environmental
   Conditions

1. Time
   of Day

2. Head
   Position and Alignment

3. Health
   Status

4. Consistent
   Measurement Techniques

Limitations

1. Fatigue

1. Accommodation

2. Previous
   Visual Tasks e.g. Working on Computer

Analysis

Primary data
analysis

Size of pupil: 3 mm

• Z (2,-2) Oblique Astigmatis

• Z (2,0) Defocus

• Z (2,2) WTR/ART Astigmatism

• Z (3,-3) Oblique Trefoil

• Z (3,-1) Vertical Coma

• Z (3,1) Horizontal Coma

• Z
  (3,3) Horizontal Trefoil

Statistical
analysis

1.
Normal distribution?

 Lilliefors
test

2.
Test for differences between M, J0 and J45 components

each

 Bland-Altman
analysis

 if
normal distribution: 1-way ANOVA

 if
not: Kruskal-Wallis

3.
Test for differences in time duration

 Excell
time calendar

Project management

Time schedule

Start:
02/2025

End:
11/2025

Preparation:
03/2025

Measurements:
03/2025

Analysis:
10/2025

Writing:
11/2025

QM / Supervision

Monthly
meeting with supervisor

Risk assessment

No
risk for study participant, as only CE certified devices are

Further project idea(s)

Difference
betwen Oculenz and digital Amblyz™ amblyopia device